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// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/backlight.h>
#include <linux/export.h>
#include <linux/fb.h>
#include <linux/mutex.h>
#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
/*
* This function generates a linear backlight curve
*
* 0: off
* 1-7: min
* 8-127: linear from min to max
*/
void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
{
unsigned int i, flat, count, range = (max - min);
mutex_lock(&fb_info->bl_curve_mutex);
fb_info->bl_curve[0] = off;
for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
fb_info->bl_curve[flat] = min;
count = FB_BACKLIGHT_LEVELS * 15 / 16;
for (i = 0; i < count; ++i)
fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count);
mutex_unlock(&fb_info->bl_curve_mutex);
}
EXPORT_SYMBOL_GPL(fb_bl_default_curve);
struct backlight_device *fb_bl_device(struct fb_info *info)
{
return info->bl_dev;
}
EXPORT_SYMBOL(fb_bl_device);
void fb_bl_notify_blank(struct fb_info *info, int old_blank)
{
bool on = info->blank == FB_BLANK_UNBLANK;
bool prev_on = old_blank == FB_BLANK_UNBLANK;
if (info->bl_dev)
backlight_notify_blank(info->bl_dev, info->device, on, prev_on);
else
backlight_notify_blank_all(info->device, on, prev_on);
}
#endif
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